What are the precautions when using the 4284A LCR Meter with the 42841A Bias Current Source and the 42842A/B Fixtures?

Below is an outline of considerations and precautions when using the Keysight 4284A with 42841A and 42842A/B external bias current source fixtures:

When powering off the 42841A:
a) Turn off the DC bias output current.
b) Disconnect the device under test (DUT) from the test fixture.
c) Turn the 42841A ON/OFF line switch to the OFF position.
d) Note that powering off the 42841A with a DUT connected may damage the 42841A internal circuitry.

Warning: The 42842B can be used in a 20A current bias system. In this configuration hazardous voltage will exist at the unused bias current input connector of the 42842B. Place the red protective connector caps on unused input connectors of the 42842B. DO NOT place a conductive object over the unused 42842B input connector. If a conductive cover is placed over the terminals, the hazardous voltage will be present at the input connector which will cause damage to the 42841A.

Close the 42842A/B/C Bias Current Test Fixture cover prior to setting up the measurement conditions.

DO NOT place the DUT in close proximity to the side panel of the 42842A/B/C DUT box. The side panel of the DUT compartment may be damaged by heat from the DUT.

The device under test, terminals, and adjacent area may become hot due to high power dissipation of the DUT. Use caution when exchanging test devices.

DO NOT allow the temperature of the DUT to exceed 180 degree C as damage to the 42842A/B/C side panels may occur.

Disable the DC Bias Output. When the measurement is complete DC bias current is still flowing through the DUT until the DC bias is disabled. Turn OFF the DC bias via the DC BIAS key on the 4284A/4285A front panel to prevent overheating the DUT. The DC bias on/off LED indicators on the 4284A/4285A and the 42841A will extinguish simultaneously.

Warning: Very high voltages (potentially kilovolts) may be generated if an inductive circuit is opened while high DC bias current is flowing thru it. The stored energy is proportional to the square of the current. To avoid this hazard, turn the bias off before disconnecting the device under test from the 42842A/B Bias Current Test fixture. Failure to perform this step may cause high current flow thru the 42841A resulting in damage.

Warning: The 42842A/B/C mounted on the 42841A must be placed such that it can be supported by the workbench. Do not stack three units (two 42841As and a 4284A) on top of each other. Also, do not place anything on the 42842A/B/C test fixture. Please, do not lean on the test fixture. Failure to adhere to these recommendations may result in the instrument falling over.